Tropical Tree Growth and Longevity: Validation of Growth Simulation,a Bootstrapping Model     

Mariby Cruz  Milton Lieberman 《Journal of Sustainable Forestry》2020,39(7):674-691

ABSTRACT

Growth Simulation, an analytical modeling technique, has been increasingly used in ecological studies and practical forestry applications where dendrochronology is not applicable. The technique uses randomly sampled diameter increments from tagged trees over a known time interval to assemble a statistical sample of lifetime growth trajectories. We carried out a validation of Growth Simulation using a temperate species in order to compare indirect model outputs with direct tree ring analysis. Rings were measured on sample disks cut from 55 pine branches ranging in age from 8–36 years. Assessments included lifetime growth rates, growth rate with respect to diameter and age, periodic annual increment (PAI), cross-referencing of rings by date, and autocorrelation of growth over successive periods. Tree ring analysis and Growth Simulation showed close correspondence for all parameters tested (maximum, median, and minimum growth rates; longevity estimates). Growth Simulation is found to be a robust and informative technique for studies of tropical tree growth, and is especially useful where analysis of tree rings is not feasible or when bootstrapping analysis of ring data is of interest.  相似文献   

Tropical Timber Trade Flows in P.R. China     

HU Yanjie LIN Fengming SHI Kunshan Research Institute of Forestry Policy  Information  Chinese Academy of Forestry  Beijing  P.R.China 《中国林业科技(英文版)》2007,6(2):62-73

The historical transition of timber distribution pattern in China was presented firstly with main parts of timber flows in China, which included timber markets, timber transport system and regulations of timber transport. Based on the overview on tropical timber flows in China, the trade flows of tropical timber from production and imports of tropical timber to export of tropical timber products were analyzed by vivid illustrations. At the same time, problems in timber trade flows in China were analysed in the end.  相似文献   

Upland agriculture,the land frontier and forest decline in the Philippines     

D. M. Kummer 《Agroforestry Systems》1992,18(1):31-46

Population pressure, expansion of small-scale agriculture and shifting cultivation are commonly cited as the causes of tropical deforestation. A close examination of deforestation and agriculture in the Philippine uplands reveals, however, that the vast majority of agriculturists must be sedentary farmers. In addition, the importance of population pressure as a cause of deforestation in the Philippines cannot be supported by the available evidence. Lastly, the concept of arable land is shown to be of limited value in discussing upland agriculture in the Philippines.  相似文献   

Treatment of tropical forages with exogenous fibrolytic enzymes: effects on chemical composition and in vitro rumen fermentation          下载免费PDF全文

A. Díaz  M. J. Ranilla  L. A. Giraldo  M. L. Tejido  M. D. Carro 《Journal of animal physiology and animal nutrition》2015,99(2):345-355

The effects of three treatments of fibrolytic enzymes (cellulase from Trichoderma longibrachiatum (CEL), xylanase from rumen micro‐organisms (XYL) and a 1:1 mixture of CEL and XYL (MIX) on the in vitro fermentation of two samples of Pennisetum clandestinum (P1 and P2), two samples of Dichanthium aristatum (D1 and D2) and one sample of each Acacia decurrens and Acacia mangium (A1 and A2) were investigated. The first experiment compared the effects of two methods of applying the enzymes to forages, either at the time of incubation or 24 h before, on the in vitro gas production. In general, the 24 h pre‐treatment resulted in higher values of gas production rate, and this application method was chosen for a second study investigating the effects of enzymes on chemical composition and in vitro fermentation of forages. The pre‐treatment with CEL for 24 h reduced (p < 0.05) the content of neutral detergent fibre (NDF) of P1, P2, D1 and D2, and that of MIX reduced the NDF content of P1 and D1, but XYL had no effect on any forage. The CEL treatment increased (p < 0.05) total volatile fatty acid (VFA) production for all forages (ranging from 8.6% to 22.7%), but in general, no effects of MIX and XYL were observed. For both P. clandestinum samples, CEL treatment reduced (p < 0.05) the molar proportion of acetate and increased (p < 0.05) that of butyrate, but only subtle changes in VFA profile were observed for the rest of forages. Under the conditions of the present experiment, the treatment of tropical forages with CEL stimulated their in vitro ruminal fermentation, but XYL did not produce any positive effect. These results showed clearly that effectiveness of enzymes varied with the incubated forage and further study is warranted to investigate specific, optimal enzyme‐substrate combinations.  相似文献   

几种热带果树在闽东南园林应用探讨     

陈鑫辉 《福建林业科技》2006,33(4):189-191,204

大多数木本常绿热带果树在闽东南适应性良好,有较高的经济开发价值和园林应用前景。针对目前闽东南水果品种不丰富和应用于园林绿化材料单调、配置单一的现状。在介绍几种新、优热带果树资源的基础上,探讨热带果树的开发前景和提出把热带果树应用于城市园林绿化建设的新思路,以丰富植物多样性和园林景观。  相似文献   

当代中国热带庭园与传统岭南庭园的历史情结     

王晓明  陈展川 《广东园林》2014,(3):29-32

文章分析传统岭南庭园的造园艺术在当代热带庭园设计中的运用和发展,重点对空间渗透交流、视线与空间序列、花木营造等方面进行分析,找寻其中的历史情结,以期为中国当代热带庭园的传承与创新提供一些参考。  相似文献   

Blood oxygen transport and hemoglobin function in three tropical fish species from northern Australian freshwater billabongs     

R.M.G. Wells  J. Baldwin  R.S. Seymour  R.E. Weber 《Fish physiology and biochemistry》1997,16(3):247-258

The oxygen binding properties of whole blood and hemoglobin were studied in three phylogenetically distant tropical teleosts inhabiting freshwater billabongs that exhibit marked seasonal oxygen stratification. The water breathing saratoga (Scleropages jardinii, Family Osteoglossidae), derived from an ancient divergence of the stem line leading to all other extant teleosts, has a low blood oxygen carrying capacity, Bohr and Root effect, and a high blood oxygen affinity. Erythrocytes contain a single major hemoglobin component, and equimolar concentrations of ATP and GTP. The tarpon (Megalops cyprinoides, Family Megalopidae), a facultative air-breather, has the highest blood oxygen carrying capacity and Bohr effect, and a low blood oxygen affinity and Root effect. Erythrocytes contain a single major hemoglobin and ATP as a putative regulator of hemoglobin oxygen affinity. Barramundi (Lates calcarifer, Family Centropomidae), is an obligate water-breather with intermediate blood oxygen binding properties, and the smallest Root effect. Erythrocytes contain at least 7 hemoglobins, and equimolar concentrations of ATP and GTP. Functional properties of these three blood oxygen transport systems are considered in terms of the respiratory environment and demand for oxygen. Our interpretation supports the hypothesis that the process of speciation can lead to divergence in physiological mechanisms, irrespective of past or present selection pressures.  相似文献   

Visualisation of standardized life-history patterns   总被引：1，自引：0，他引：1  

Dirk Zeller  Daniel Pauly 《Fish and Fisheries》2001,2(4):344-355

The life‐history patterns of fish and invertebrate species are complex. But much of this complexity can be captured in simple diagrams of coastal transects, where juveniles usually occur in larger numbers in shallow waters, while adults generally inhabit deeper, offshore waters. Iconographic representations of generalized life‐history patterns and depth profiles, with specific key life‐history parameters can capture much of these standardized patterns, including spawning areas, nursery/juvenile distributions, adult distributions and spawning migrations. Several examples presented here from a wide range of habitats and ecosystems (temperate and tropical waters, demersal, deep water, pelagic and coral reefs), including an example of different stocks of the same species, illustrate some general patterns with regard to water depth and distance from shore. The present approach should be viewed as a first step towards obtaining standardized patterns about key life‐history parameters, and will hopefully lead to incorporation into management of life‐history interconnectivity between different fishery sectors or gears. This may contribute to sustainable, ecosystem‐based approaches to management by informing policy options when faced with decisions to rationalize overcapitalized fisheries.  相似文献   

Hypoxia-based habitat compression of tropical pelagic fishes   总被引：2，自引：0，他引：2  

ERIC D. PRINCE  C. PHILLIP GOODYEAR 《Fisheries Oceanography》2006,15(6):451-464

Large areas of cold hypoxic water occur as distinct strata in the eastern tropical Pacific (ETP) and Atlantic oceans as a result of high productivity initiated by intense nutrient upwelling. We show that this stratum restricts the depth distribution of tropical pelagic marlins, sailfish, and tunas by compressing the acceptable physical habitat into a narrow surface layer. This layer extends downward to a variable boundary defined by a shallow thermocline, often at 25 m, above a barrier of cold hypoxic water. The depth distributions of marlin and sailfish monitored with electronic tags and average dissolved oxygen (DO) and temperature profiles show that this cold hypoxic environment constitutes a lower habitat boundary in the ETP, but not in the western North Atlantic (WNA), where DO is not limiting. Eastern Pacific and eastern Atlantic sailfish are larger than those in WNA, where the hypoxic zone is much deeper or absent. Larger sizes may reflect enhanced foraging opportunities afforded by the closer proximity of predator and prey in compressed habitat, as well as by the higher productivity. The shallow band of acceptable habitat restricts these fishes to a very narrow surface layer and makes them more vulnerable to over‐exploitation by surface gears. Predictably, the long‐term landings of tropical pelagic tunas from areas of habitat compression have been far greater than in surrounding areas. Many tropical pelagic species in the Atlantic Ocean are currently either fully exploited or overfished and their future status could be quite sensitive to increased fishing pressures, particularly in areas of habitat compression.  相似文献   

Copepod species diversity and climate variability in the tropical Atlantic Ocean   总被引：4，自引：0，他引：4  

Sergey A. Piontkovski  Michael R. Landry 《Fisheries Oceanography》2003,12(4-5):352-359

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